Ideal Weight Calculator: Formulas and What They Mean
Ideal Weight Guide
An ideal weight calculator gives a rough target weight based on your height and sex. These figures come from formulas designed decades ago for clinical dosing, so they are useful reference points rather than strict goals. Body composition, frame size, and muscle mass all matter, which is why "ideal" should be read loosely.
The Devine formula
The most widely used formula is Devine, which starts from a base weight at five feet of height and adds a fixed amount for every inch above that.
Men: 50 kg + 2.3 kg per inch over 5 ft
Women: 45.5 kg + 2.3 kg per inch over 5 ft
A worked example
For a man who is 5 ft 10 in — that is 10 inches over five feet:
50 + (2.3 × 10) = 50 + 23 = 73 kg
So the Devine "ideal" is about 73 kg. A calculator does this instantly and can show the other formulas side by side.
Other formulas
Several variations refine Devine's numbers. The Robinson and Miller formulas adjust the base and per-inch values slightly, while the older Hamwi formula was created for quick bedside estimates. They all follow the same height-based logic and produce results within a few kilograms of one another.
A healthy BMI range as an alternative
Because these formulas ignore build, many people prefer a healthy weight range from BMI instead. A BMI between 18.5 and 24.9 is considered healthy for most adults, which translates to a span of weights for any given height rather than one number.
How to use the calculator online
- Enter your height.
- Select your sex.
- Read the ideal weight from each formula.
- Compare against a healthy BMI range for context.
This is general information, not medical advice. A doctor or dietitian can account for your build, activity, and health history.
FAQ
Q: Which formula should I use?
A: Devine is the most common, but comparing several gives a more realistic range than trusting a single number.
Q: Is "ideal weight" the same as "healthy weight"?
A: Not exactly. Ideal-weight formulas output one figure; a healthy BMI range gives a band of weights that suit more body types.
Q: Do frame size and muscle matter?
A: Yes. A muscular or large-framed person can weigh more than the formula suggests while still being healthy, since these formulas do not measure body composition.